Open hole gas well closed cycle drilling and production system without gas venting and flaring or reservoir damages

ABSTRACT

An open-hole drilling method and process is embodied in creation of a closed cycle and system for extracting gas from shale and other impermeable and natural vertical fracture dominated reservoirs. The closed cycle system enables gas from reservoir to be used as a drilling fluid, with any excess gas produced as the wellbore is extended, to be sold in real time through a gas pipeline. Since only natural gas exists throughout the closed system, no risk exists for downhole explosions, and no wellbore damages occur from foreign fluids, such as mud, cement, and water. Limits of wellbore length due to gas produced while drilling, and risks during gas flaring are eliminated. All products produced from wellbore are captured so no venting of any liquids, gases, or solids. All hydraulic fracturing issues are avoided. Gas flow rate measurements while drilling enables technical, financial, reserve estimate models development in real time.

CROSS-REFERENCE TO RELATED APPLICATION

“Not Applicable”

BACKGROUND OF THE INVENTION

The great gas and oil reserves discovered in the Marcellus Shale and theUtica Shale in the extended Appalachian Basin have generated tremendousefforts to recover these natural resources. Somewhat like other lowporosity, low permeability oil and gas formations with huge reserves,these shales present recovery issues challenging to the mostsophisticated in the industry. The Marcellus Shale is known for itshierarchical natural fracture networks and systems that largelyconstitute the reservoir, ranging from the nano scale to large macroscales of feet and miles. The most dominant macro scale fractures arevisible not only in the shales, but also in outcrops throughout theworld, and are widely known as “the natural vertical fracture systems”,or joints, which also extend vertically below 10,000′ and have a generaltrend of about N45° E in Appalachia. These vertical natural fracturesystems are the primary conduit for oil and gas to migrate to thewellbores drilled in the shales, especially now for horizontal,directionally drilled wells. Recovery and success of wells drilledthrough these shales is so dependent upon them that wellbores areoriented so as to intersect the maximum number of them at large anglesof the order of 90°, at N45° W. However, completing wells bystimulation, such as hydraulic fracturing, following drilling of theboreholes, such that the hierarchical fracture networks connect to andremain open sufficiently for drainage to the wellbores is the realchallenge facing the industry. In essence, technologies that evolvedthroughout oil and gas extraction history for competent sandstones,limestone, and other hard rocks are being applied to the shales. Thishistoric technology that involves over 8 major steps or phases ofdrilling, cementing pipe, perforating pipe, creating 100 or more ofstages, setting plugs, hydraulic fracturing using 1,000's of barrels ofsand laden water, drilling out plugs, and well cleanout, all requiring1,000's of large truck trips of products is extremely time consuming,expensive, destructive to roads and the environment. The oil and gasindustry is desperate for better extraction technology.

This inventor has created inventions leading to patents in this realmsince 1974, and more recently this application is an outgrowth of one,U. S. application Ser. No. U.S. Provisional Patent application Ser. No.61/650,259 filed on May 5, 2012, “Method of Further Fissuring a NaturalVertical Fracture System in order to Improve Connectivity between a PayZone of a Petroleum and natural Reservoir and a Horizontal Wellborethrough a Sedimentary Stratum”, but was paused because a disclosurerequirement for the “perturbation” claimed in the application would havegiven the methodology to the world, and would have been very difficultto enforce in deep wells underground anywhere, but especially intypically remote and inaccessible locations. This application includesthe methodology in that application and much more. This applicationincludes additional processes and methodologies that combine to achievethree distinctive effects, each of major consequence in the extractionand production of oil and gas. First, it may be observed that themethodology disclosed in this patent application is a one stage, orstep, or phase process, as starkly contrasted to the classicalextraction 8 phase, and over 100 stages process described above.

Beyond the huge issues in the major 8 phase and 100 stage process ofcost, time consuming, hydraulic fracturing with huge volumes of productsrequired, and damages to roads and the environment, the results are evenunsatisfactory. It is an established fact that after nominally 2 years,the decline curves for Marcellus Shale wells drilled throughout theAppalachian Basin where the Marcellus exists, take a severe negativeslope corresponding to about 80% decline from initial production. It isfurther more meaningful and disturbing when interpreted to mean thatonly about 7% to 20% of the original resources in place are beingrecovered. It is even more disturbing to know that all the methodologiesused in the drilling and completion of these wells today, not onlyrecover only 7% to 20%, but permanently seal off the majority of the allimportant natural fracture networks such that the remaining resourcesare “entombed” and never recoverable regardless of any future completionmethodology, including classical secondary and tertiary concepts. Thisconstitutes a U. S. National security issue pertaining to long-termrecovery of our National energy reserves, as well as, a devastatingimpact on the mineral owner(s), that the remaining 80% to 93% of theirminerals are forever lost. Since these same recovery technologies areused world wide, it also constitutes a permanent loss of more than 50%of the world's oil and gas resources used for energy and all thepetrochemical based products enjoyed by humans. These phenomena are aresult of what is called “formation damage”. The rest of the story isthat other major low permeability reservoirs in the U. S., and perhapsother parts of the world, also exhibit this rapid 80% decline after twoyears or less of production because the same methodology is applied toall reservoirs around the world. These phenomena contain some veryimportant messages. First, the present technologies and methodologiesmust immediately change! Second, the mechanisms contributing to thesephenomena must be identified, characterized, and avoided in futuremethodologies, which is the essence of this patent application. Thereare four readily identifiable formation damage mechanisms. The first isa result of using drilling mud in the drilling process, which carriesthe drill cuttings back to the top of the ground for disposal, and isalso beneficial in well control, borehole stability, etc. However, thenegatives greatly outweigh the positives, since this mud with thethousands of psi hydrostatic pressure plugs off the only major conduitsof hierarchical natural fracture networks, being the main conduits tothe wellbore, for perhaps 100's of feet away from the wellbore.

The second mechanism is that when the mud is flushed from the wellboreand pipe is run into the wellbore to be cemented back 7,500' as in theMarcellus Shale to the surface, the extreme hydrostatic pressures of3,500 psi plus pumping pressures exceeding 4,000 psi on the cementfurther opens and penetrates the main natural vertical fracture conduitsand permanently seals the hierarchical natural fracture networks, againradiating far out into the reservoir, such that the cementing andhydraulic fracturing process leaves about 50% to 80% of the reservoir“entombed” in blocks, and never to be recovered. The third and fourthmechanisms of reservoir damage occur during the hydraulic fracturingprocess of this shale with problematic mechanical properties. Thesedamaging mechanisms are in addition to the multiple water effects andother negatives. Again, these phenomena are believed by this inventor tobe the same problem that also occurs in many other oil and gasreservoirs in the world, based upon their symptomatic similar rapiddecline curves in the second year. During fracturing, the in situ stressfield adjacent and far remote from the wellbore is modified in suchwanner as illustrated in the Shuck U. S. Pat. No. 4,005,750, Feb. 1,1977, “Method for Selectively Orienting Induced Fractures inSubterranean Earth Formations”. Due to the low mechanical ultimatecompressive and shear strengths of the shale being exceeded during thisprocess, a 3-D cage or shield of failure damage occurs that destroys theotherwise communicating hierarchical network of frqctures. Thisformation damage mechanism is not reported in the literature. The fourthmechanism is actually a phenomena associated with: a) the earth's insitu stress field and differences in maximum and minimum principalstresses, b) natural vertical fractures and the stress concentrationfactors at the tip of a propagating fracture as in fracture mechanics,c) the fabric of the fractured network, and d) the nature of the designprocess of perforating steel pipe to hydraulically fracture thereservoir rocks. The culmination of effects of these four mechanisms isthat once an induced hydraulic fracture intersects a natural verticalfracture, it will follow it extensively, in two directions in an upwardmanner until conditions for propagating a new orthogonal set offractures evolve. There are also other multiple mechanisms documented inthe literature, beginning with the drilling process, that tend to plugoff the natural fracture networks. The exact magnitudes of their impactare not precisely documented. These mechanisms have led to variousmethods of controlling the downhole pressures, such as, underbalanced,managed pressures, etc. The Marcellus Shale is also known throughout thehistory of drilling deep wells below the Marcellus to be a problem zone.This is because it often presents a high risk of getting the drillingtools “stuck in the hole” and can lead to loss of the well. The detailedmechanisms by which this occurs have never been quantified in anengineering manner or at least reported as such in the literature tothis inventor's knowledge. However, it is known that usually drilling toreach rock formations below the Marcellus is done by drilling on airdown to within a couple hundred feet above the Marcellus and then“mudding up”, by using drilling mud (much as today in drilling withinthe Marcellus) to drill and complete wells for any purpose below theMarcellus, as a means of not getting drilling tools stuck in the hole.

Thus, there is much to be concerned about in extracting oil and gasreserves from all types of reservoirs around the world, in addition tothe profound and well documented reservoir damage and 80% decline curvesthat must be avoided if at all possible in drilling through or withinthe Marcellus and other Shales, and other sensitive property earthensubstances. There are also many issues associated with water usage,sources, transportation, and disposal in addition to formation damage.Gas flaring and general venting anything from the wellbore into theatmosphere are issues that have gained National public and Governmentattention and President Obama and the U. S. Environmental ProtectionAgency advocated and almost implemented regulations that everythingcoming out the top of an oil or gas well must be captured and not ventedto the atmosphere. If this had been strictly enforced, it would haveeliminated all oil and gas well drilling because the technologies didnot exist to accomplish the zero emissions. Therefore, a real urgencyexists and time is of the essence. This invention is actually abreakthrough effort and process. This method and process constitutes anachievement advocated by the U. S. Government over ten years ago, andcould prevent future shutting down drilling of all oil and gas wells inthe United States. Thus, this can be a transformational milestonemethodology and process.

This closed cycle system and process is designed to be implemented onlyfor the horizontal lateral wellbore that begins at the precipice of thepay zone of interest, in this example case, the Marcellus Shale. Thissystem and process is not limited to the Marcellus Shale, and can beapplied to any oil or gas pay zone of interest at any depth, whether ornot a shale rock formation. In applying this system and process, thevertical well with all of the conventional protective strings ofvertical pipe, typically three, are cemented into place as usual. Thisvertical well can stop at a distance of typically 500′ above the bottomof the pay zone of interest in such manner that the 500′ radius curve toget 90° from vertical is then drilled down to and through the Shale andleft open hole. More typically, the vertical well will be drilled onaround the curve through the Marcellus Shale, such that when the 90°horizontal point is reached, it is also at the desired depth startingpoint within the Shale where the lateral will begin to be drilled, oftenin a 75′ thick pay zone about 20′ up from the bottom of the pay zone.Thus, the last string of pipe is inserted beyond the vertical point allthe way around the curve, called the heel, and then cement is circulatedfrom the bottom of the steel pipe at the bottom of the curve all the wayup the annulus to the top of the ground. In this manner, the horizontallateral actually begins at the end of the steel pipe which is located atthe tangent point when the curve just becomes horizontal. The 500′radius allows the steel pipe to be sufficiently bent to go around thecurve. This assures that no gas will leak by the pipe out of the payzone interval. At this time a substantial seal exists down to the end ofthe steel pipe. The drilling tools can also negotiate this 500′ radiuswithin the steel pipe and at the horizontal point begin to drill thelateral after the total system is flushed, scavenged and purged of allgases or liquids that may remain following the cementing of the laststring of pipe, and pressure tested with only natural gas throughout thesystem.

BRIEF SUMMARY OF THE INVENTION

The closed cycle system illustrated in FIG. 1 functions in the followingsimplified manner. Natural gas is purchased by opening master valve A1which is connected to a gas sales and purchasing master meter A2, whichis then connected to a gas purchasing and sales pipeline A3, whereupongas, flows through pipeline (A1 to C1) and compressed by C1 to scavenge,purge, pressurize and pressure test the entire system piping network,starting with B and cycling through C2, E, F, G, H and pipelines (H toA), and (G to B). Following startup safety and operational protocols,gas circulation begins, the drill bit encounters the pay zone withprescribed bit pressure, and drilling begins and continues to finallength. All pipes and connections in this closed cycle are conventionalhigh pressure pipes rated above 10,000 psi and typically connected andsealed with conventional hammer unions and not disconnected duringentire process. During the lateral drilling process additional pipejoints are added using a hydraulic type fitting with O-ring type sealsthat prevent pressure loss during added joints makeup and drilling. Whengas produced by the well while drilling exceeds that required fordrilling, the excess gas, instead of being flared conventionally, iscycled back through the F, G and H system shown in FIG. 1, and thenpasses back through a master valve A1 and gas master flow meter A2 intoa gas sales pipeline A3.

Most issues discussed in Background above are circumvented by thiscomprehensive closed cycle system which constitutes a one-step orone-phase process when compared to conventional drilling, cementingpipe, perforating, fracking, and well clean up taking several weeksprior to selling gas into a pipeline.

BRIEF DESCRIPTION OF THE DRAWINGS

The aforementioned and other aspects, features and advantages can bemore readily understood from the following detailed description withreference to the accompanying drawings wherein:

FIG. 1 shows the major components and functionality of this closed cyclesystem are illustrated.

DETAILED DESCRIPTION OF THE INVENTION

Basic Closed Cycle System Functionality

The closed cycle system illustrated in FIG. 1 functions in the followingsimplified manner. Natural gas is purchased by opening master valve A1which is connected to a gas sales and purchasing master meter A2, whichis then connected to a gas purchasing and sales pipeline A3, whereupongas, flows through pipeline (A1 to C1) and compressed by C1 to scavenge,purge, pressurize and pressure test the entire system piping network,starting with B and cycling through C2, E, F, G, H and pipelines (H toA), and (G to B). Following startup safety and operational protocols,gas circulation begins, the drill bit encounters the pay zone withprescribed bit pressure, and drilling begins and continues to finallength. All pipes and connections in this closed cycle are conventionalhigh pressure pipes rated above 10,000 psi and typically connected andsealed with conventional hammer unions and not disconnected duringentire process. During the lateral drilling process additional pipejoints are added using a hydraulic type fitting with O-ring type sealsthat prevent pressure loss during added joints makeup and drilling. Whengas produced by the well while drilling exceeds that required fordrilling, the excess gas, instead of being flared conventionally, iscycled back through the F, G and H system shown in FIG. 1, and thenpasses back through a master valve A1 and gas master flow meter A2 intoa gas sales pipeline A3.

This basic closed cycle system, one-phase process, and simultaneouscombined drilling and well-completion methodology incorporate subsystemsthat create versatility, features, and results also unique to theindustry. The methodology is described first.

Methodology

For many reasons described above under Background that are distinctlydifferent from this herein methodology, it is hereby made a part of thisSpecification. It is of paramount importance to use in the drillingprocess through a friable and sensitive rock formation, such as theMarcellus and other Shales, a drilling fluid that does not damage in anyway the ability for gas to flow from the rock, it's matrix or naturalfracture network system, into a penetrating wellbore. Thus, the minimumrestriction of an uncased borehole without steel pipe cemented in, orany sleeves is a fundamental condition and objective of thismethodology. This is known as an “open-hole” well completion method. Thevarious unique embodiments of this methodology include:

1. The natural gas drilling fluid used is in a gaseous thermodynamicstate, without presence of any oxygen or water molecules. Since no air,drilling mud, cement, or any other oxygen containing compound isintroduced into the wellbore during or after drilling, this methoduniquely constitutes both an oxygen-free drilling, and well-completionmethod and process. The hypoxia or anaerobic down-hole environmentthusly created entirely eliminates the risk and preventative measuresnormally taken for downhole explosions.

2. The drilling fluid is a hydrocarbon of the same general chemicalcomposition as the native fluid stored in the rock formation, known asnatural gas, which may have innumerable hydrocarbons, all combustible orexplosive when combined with oxygen under various conditions. However,this fluid being reintroduced to the rock faces does not in any mannerdamage the ability of the rock to allow gas to flow into the wellbore.

This is in stark contrast to use of water with viscosity and surfacetension plugging small fractures and prohibiting gas tlow.

3. This unique method utilizes the native fluid of natural gas from thegas reservoir as the drilling fluid, starting from the beginning of thedrilling process and rapidly increasing to 100% after the primingnatural gas of essentially the same composition obtained from the gassales pipeline is displaced and returned to the gas sales pipeline fromwhich it was obtained. In essence, the startup priming natural gas fromthe sales pipeline is just “borrowed” for a very short period andquickly returned to the sales pipeline from which it was obtained. Thismethod has never been used, and is a dramatic and unprecedentedachievement.

4. The rapidity with which the borrowed priming natural gas is displacedand replaced as the drilling fluid occurs in dramatic steps, typicallyevery 3′ to 10′ of borehole drilled, as each natural vertical fractureis intersected. This is a result of the Marcellus and other Shaleshaving nano order of matrix permeability, while the vertical fractures,the main conduits to the wellbore, have permeabilities of 3 to 6 orhigher orders of ten magnitude of permeability. This rapid entry of gasfrom the fractured reservoir into the wellbore largely constitutes“excess” gas that would normally be vented to the atmosphere or flaredin exiting the above ground piping annulus. In this unique,unprecedented method, this gas is returned to the sales pipeline on acontinuous, steady basis.

5. Ordinarily, gas sales pipelines laid to the pad and connected in anyway to any pipe connected to the drilled well are the last step in thedrilling and completioiu process for a wide variety of reasons. However,in this method, laying a gas sales pipeline up to the pad, andconnecting it to a drill pipe is one of the initial steps in this methodand process.

6. This “selling-gas-while-drilling” method also enables other processesto be introduced, including:

a) The economic success of the well is measured continuously, every footof wellbore drilled and every natural fracture intersected by thewellbore, because the gas is going through a sales gas meter, which canbe remotely monitored either in an onsite van monitoring and controlstation, or over the internet. This means that economic algorithms canbe used in real time every step of the way to calculate the value ofreserves being recovered using existing reservoir models, which may alsoprovide bases of when to stop drilling based upon any economic or riskmodels.

7. In fact, this methodology enables and allows for the first time, thereal-time research task of creating new reservoir models for naturallyfissured and fractured reservoirs and calibrating them based not onlyupon real gas flow quantities recovered, but all of the precisegeological, natural gas and petroleum engineering conditions and dataexisting at the specific site to be input to the onsite computer systemapriori to drilling, such that immediately after the well is drilled,RESERVES ESTIMATES for the ultimate production for the life of the wellcan be made available to investors and the users of technical data andmodels. This is again a monumental capability and achievement for theindustry. Even just the basic calculations of reserves estimates arecurrently conventionally made days and months after the well is drilled.The real-time creation and calibration of such a model for fracturedreservoirs over an extended period of time and by large funded researchprograms is a major objective of the industry today.

8. The fact that gas flow rates into the open wellbore are measuredwhile drilling is a valuable research tool. This allows gas entry to becorrelated with major natural fracture systems, and map them, theirfrequency, and major role assessment in reserves recovery models, alluseful in creating engineering design plans for drilling and advancingtechnology in sensitive reservoirs. This enables creation of all typesof models in real time ranging from process design to financial analysisto futuristic reserve recovery efficiency and total reserves to berecovered.

9. This selling-gas-while-drilling method also reduces the currentmethodology urgency and main objective to get the lateral boreholedrilled ASAP, because the Rig cost of nominally $15,000/day is largelyoffset, since the excess gas being recovered while drilling is beingsold. That is, drilling penetration rate can be as slow as neededwithout major financial penalty.

10. This selling-gas-while-drilling method also is in stark contrast tothe current methodology limitation of having to stop drilling and removethe drilling tools from the wellbore under risky conditions, whendrilling on air or other gases or liquids, and the volumes of naturalgas being produced greatly increase risk of down-hole explosions, or canno longer be safely flared or handled by the equipment and well-controlrisks are too high. In this method, many such issues are averted, andthe length of borehole that can be drilled is greatly increased.

11. This selling-gas-while-drilling methodology enables the currentlyfeasible length of drilled laterals to be extended by 1,000's of feet,and only limited when a variety of other parameters or variables becomethe limiting factors. That is the extra gas entering following eachnatural vertical fracture intersected does not become an untenable orunmanageable problem. On the contrary it is immediately an asset.

12. This methodology also embodies a “start-stop-forward-andreverse-drill cycle” (FRDC). The friable, fissured shales are highlylikely to shear or drop slivers or blocks of shale into the drilledwellbore. These droppings are usually referred to as “wellborestability” issues, which can cause high torque on the drill collars ordrill bit assembly and the entire drill pipe to get stuck and potentialloss of the well. Thus, this FRDC can be enabled and utilized at anypoint or time deemed desirable in the entire wellbore drilling process.A conventional reaming type tool is assembled behind the main drill bitin such manner that when forward drilling or reverse retrieving thedrill pipe while still rotating, the reaming tool will crush thedroppings into fine particles that can be circulated to above groundfacilities along with all other cuttings. Several variables, such asdrill pipe torque, reduction in steady flow of cuttings, downholepressures, volumes of gas being produced, etc. can be used for decisionmaking to determine two characteristics of the FRDC process, namely a)the stroke amplitude of the FRDC, and the frequency of utilization ofthe FRDC. Once again, while rig cost is a decision making parameter,these other downhole parameters also become strong variables in thedecision making of the drilling engineer. This FRDC can also beconsidered a safety factor to be used frequently to avert risk ofgetting tools stuck in the wellbore.

13. This FRDC also is a process that functions without needing to knowthe unknown shale mechanical properties of moduli, such as the classicalYoung's Modulus, shear and bulk moduli, defined and used forconventional elastic, isotropic, and homogeneous material properties.When the in situ stress field of 1,000's psi is removed in creating theopen borehole, the shale expands in all three dimensions in response tothe three different magnitudes of in situ stresses along the borehole.This expansion in 3-D has various implications, one of them being theradial expansion toward the centerline of the borehole axis. This radialexpansion will result in a reduction of wellbore diameter in real timewhile drilling, which will likely also contribute in various ways to theresulting named wellbore instability issue. This FRDC process allowsthis to happen in a less catastrophic and controlled or managed manner.That is, in contrast just to taking the bit to the reservoir rock anddrilling the borehole forcibly and aggressively at maximum speed, thisFRDC allows the reservoir rock to come to the bit in acontrolled-managed manner. This method and process does not require anyadvance knowledge of the relative magnitudes of the horizontal-beddingplane in situ stresses or their differences, or the material mechanicalproperties. The FRDC method and process deals with these many possiblemechanisms and above mentioned unknown material properties and behaviorsof this fissured material in such a manner they are to a significantdegree ameliorated by the FRDC.

14. This FRDC is the sub-process that is enabled by the closed cyclesystem, process and methodology, which constitutes both a combined“drilling” and “well-completion” process, which is always a separate anddistinctly different process in all oil and gas well drilling operationstoday. This FRDC is in stark contrast to the hydraulic fracturingcompletion method and process used almost exclusively today, whichcreates traumatic borehole damages, and actually entombs and honeycombswith cement a high percent of the resources in place, perhaps greaterthan 60 or 70% that can never be recovered by any economic ortechnically feasible process.

15. Although one of the principal applications of this extractionprocess is solving problems for low permeability shales, it is actuallyindependent of, and not a function of many of the mechanical propertiesof the reservoir rocks, and likewise independent of the state of in situstresses of the reservoir. Therefore, it is applicable to any type ofreservoir rock or it's in situ conditions. Current methodology todayrequires calculations that involve such mechanical properties as Young'smodulus, compressive and shear ultimate strengths and elastic ranges,bulk modulus, fracture network characterization, in situ stresses, etc.These properties are incapable of being determined or even estimated insome cases. Since this method and-process do not utilize the propertiesin engineering design calculations, it is an extremely important featureof this method, system, and process. There are no completion steps, likehydraulic fracturing, staging, or fracture propping wherein suchproperties are used.

The Closed Cycle System

In this unprecedented single step or phase gas well drilling andproduction strategy and process, specially designed components allow thecreation of a closed system, and closed cycle in which the same gas orgas just previously allowed to flow into the borehole is cycled backdown the drill pipe after extracting all significant particles tocontinue drilling in a continuous, cyclic manner. Since this is acontinuous process until the planned end of the horizontal lateralborehole is reached, it is truly a one-step or one-phase process. Thisachievement is believed to be truly transformational with huge potentialfor the oil and gas extraction industry around the world. This closedcycle system, comprised of the illustrated components, functions as asingle entity in unison, such as a device or machine with single globalpurpose accomplishing a plethora of functions, and whcrein the two basicremaining conventional phases of drilling and well-completion areachieved simultaneously in one phase. This closed cycle system, whereinexcess liberated gas beyond that required for drilling is disposed of bysending it back to a gas purchasing pipeline, enables the wellbore to bedrilled to lengths dependent upon such variables as, strength of steelpipe, not quantities of gas produced from fractures that has to beflared in a wasteful and dangerous manner.

Larger Particles Separator

As the particle laden gas stream exits the tee connected to the annulusbetween the production string of pipe and drill pipe, it all passesthrough a large, high pressure vessel selected to separate the largerparticles using centrifugal and gravitational forces, shapes, andgeometrical configurations to separate the bulk of the particles fromthe turbulent gas stream. Vibrators may be strategically placed on theexterior walls of the separator to expedite particle collection atbottom of separator and mitigate side-wall sticking. The particlessettle in a collector pipe at the bottom of the pressure vessel andentrance to a large ball-type valve with full throat opening and closingat 90 degree rotational intervals. This valve opens to adepressurization chamber of such size and volume to contain theparticles during a pressure release period, which is cycled to dump theparticles into an atmospheric pressure chamber collector for disposal.This is accomplished by a second ball valve on the bottom of thedepressurization temporary storage-depressurization chamber. Thisemptying cycle period is computer controlled based upon transducerslocated on the separator.

Smallcr Particles Separator-Filter Sub-System

The characteristics of the particles suspended in the particle-gasstream at this point will vary with several variables associated withthe drilling process and the fabric of the shale being drilled. Avariety of commercially available separators and filters are used in acascade manner in this system component. The fine particles are removedto whatever specifications

as may be required by various types of compressors, and as may berequired by different pipeline companies to assure the excess gas streammeets gas sales pipeline quality standards. Appropriate modifications tothese subsystems include the same provisions of vibration, collection,depressurization chamber with two isolation ball valves and atmosphericpressure collection vessel for particle disposal as in the largerparticle separator.

Compressors

Two compressors illustrated in FIG. 1 as C1 and C2 meet the principalgas compression requirements for the closed cycle system. Since theprocess begins with thoroughly scavenging and purging the entire systemof all existing gases, and then pressurization of the entire system forleak detection, followed by drilling initiation, the two distinctcompressors are prescribed to serve these specific needs. The C1compressor is a high-pressure low-volume-rate compressor, since time orrate are not of the same order as for C2.

That is, C1 can accept gas at whatever rate the gas sales pipeline candeliver at whatever pressure, and compress it to the desired pressureestablished for the surge-storage tank reservoir during whatever time isreasonably required. The requirements of C2 are similar in size andvolume rate capacity to commercial compressors conventionally used forair drilling of wellbores. These rates for compressing the natural gasdrilling stream are not of significant difference. There is one morecompressor C3 not illustrated in FIG. 1, because it may or may not beneeded as a required component to the basic closed cycle system. C3 willbe designed and installed in the system on an “as needed” basis, whichis contingent upon different drill site conditions, including the salespipeline operating pressure. The sales pipeline rate capacity foraccepting gas would obviously be capable of handling any excess volumeproduced during drilling or routine well production, or it would nothave been laid to the drill pad in the first place. Thus, C3specifications are, in general, lower pressure and lower flow-rate thanC2, and lower pressure, but higher rate than C1.

What is claimed:
 1. A closed loop system for natural gas extraction, thesystem comprising: an external gas pipeline; a master meter valve,wherein the master meter valve supplies natural gas to the system, thesupplied natural gas is obtained from the external gas pipeline; one ormore of a first compressor, wherein the natural gas supplied from themaster meter valve flows to the first compressor so to increase gaspressure; a surge and storage tank reservoir, wherein once a desiredpressure is reached, the pressurized natural gas flows from the firstcompressor and system to the surge and storage tank reservoir; one ormore of a second natural gas compressor which receive natural gas whenneeded from the surge and storage reservoir so to deliver gas at ratesand pressures required for drilling processes; a well site, including avertical well and a drill rig; the drill rig further comprising a drillbit which is actuated by the pressurized natural gas fluid received fromwithin the system or by a rotating drill pipe; a particle separator forseparating large particle cuttings from gas circulating fluid receivedfrom the well site; a filter subsystem for removing smaller particlesthe gas circulating fluid received after being processed by the particleseparator; a natural gas stream conditioner for preparing the naturalgas suitable to enter the external gas pipeline; wherein once thenatural gas is processed by the filter subsystem, the processed naturalgas is dispersed between the natural gas stream conditioner and reentryinto the system at the storage and surge tank reservoir as needed. 2.The system as claimed in claim 1, the system further comprising: whereinthe system is closed and sealed so that no substances other than naturalgas are entered, exited or circulated within.
 3. The system as claimedin claim 1, the system further comprising: wherein the system is closedand sealed so that no substances are vented into the atmosphere.
 4. Thesystem as claimed in claim 1, the system further comprising: wherein aprimer quantity of natural gas is obtained from the external gaspipeline.
 5. The system as claimed in claim 4, the system furthercomprising: wherein after being primed, the pressurized natural gasfluid is obtained from the same gas reservoir borehole as the one beingdrilled.
 6. The system as claimed in claim 1, the system furthercomprising: wherein the system does not use any of drilling mud,cementing pipe through the pay zone, perforating pipe and hydraulicfracturing.
 7. A method using a closed loop system for natural gasextraction, the method comprising: obtaining natural gas from anexternal gas pipeline; supplying natural gas to the system from a mastermeter valve; receive the flow of natural gas from the master meter valveat one or more of a first compressors; increase gas pressure using theone or more of a first compressors to a desired pressure within thesystem; wherein the pressurized natural gas flows from the firstcompressor and system to a surge and storage tank reservoir; whenneeded, receive natural gas at one or more of a second natural gascompressors from the surge and storage reservoir so to deliver gas atrates and pressures required for drilling processes; actuating a drillbit of a drill rig using a vertical well at a well site using thepressurized natural gas fluid received from within the system oractuating a drill bit by a rotating string of drill pipe; separatinglarge particle cuttings from gas circulating fluid received from thewell site at a particle separator; removing smaller particles from thegas circulating fluid received after being processed by the particleseparator at a filter subsystem; preparing the natural gas to enter theexternal gas pipeline at a natural gas stream conditioner; wherein oncethe natural gas is processed by the filter subsystem, the processednatural gas is dispersed between the natural gas stream conditioner andreentry into the system at the storage and surge tank reservoir asneeded.
 8. The method as claimed in claim 7, the method furthercomprising; a process of completion that does not involve the injectionof any substance into the reservoir rock.
 9. The method as claimed inclaim 7, the method further comprising: wherein the natural gas producedand processed from the well site being drilled is recycled back into thesystem as drilling fluid through the system.
 10. The method as claimedin claim 9, the method further comprising: the obtained natural gas fromthe external pipeline is used to prime the system, once the system isprimed, the system then switches to used recycled natural gas.
 11. Themethod as claimed in claim 7, the method further comprising: a drillingprocess; wherein the drilling process comprises: reaming a boreholewhile drilling a directionally controlled pilot hole by forward andreverse cycles, wherein the cycles are determined manually,periodically, or based upon measured variables values to achieve atleast one of a plurality of objectives, the objectives comprising: a)cleaning the borehole of larger particles and crushing larger chunkssuitable for gas stream entrainment and circulation to above groundfacilities, b) enlarging the diameter of a borehole, and c) removing thedamaged surface due to the front end drill bit.
 12. The system asclaimed in claim 1, the system further comprising: wherein the excessnatural gas produced beyond that required for drilling is cycled backthrough the system and out to the master meter valve, wherein the mastermeter valve supplies natural gas back to a master sales meter and theexternal gas sales pipeline.
 13. The method as claimed in claim 7, themethod further comprising: wherein the excess natural gas producedbeyond that required for drilling is cycled back through the system andout to the master meter valve, wherein the master meter valve suppliesnatural gas back to a master sales meter and the external gas salespipeline.
 14. The system as claimed in claim 1, the system furthercomprising: wherein the system is hypoxia or anaerobic oxygen-free suchthat no internal system explosions can occur.
 15. The system as claimedIn claim 1, the system further comprising: wherein after theconventionally drilled vertical well is drilled and completed, thesystem does not use any water on the drill pad, so to eliminate therisks of spills, prevent environmental violations, and preventenvironmental damage to any adjacent water, ponds, creeks, streams, orrivers.
 16. The method as claimed in claim 7, the method furthercomprising: wherein after the conventionally drilled vertical well isdrilled and completed, water is not used on the drill pad, so as toeliminate the risks of spills, prevent environmental violations, andprevent environmental damage to any adjacent water, ponds, creeks,streams, or rivers.
 17. The method as claimed in claim 7, the methodfurther comprising: wherein a closed cycle extraction process isindependent of mechanical properties of reservoir rock or its states ofin situ stress field.
 18. The system as claimed in claim 1, the systemfurther comprising: real time gas flow rate data from a master flowmeter, which are used in real time to create computer models includingreserve estimates.
 19. The method as claimed in claim 7, the methodfurther comprising: calculating reserve estimates, by using real timegas flow rate data in conjunction with the real time created computermodels.
 20. The system as claimed in claim 1, the system furthercomprising: wherein a length of drilled borehole that can be drilled isnot limited as a result of an amount of gas liberated into a wellborewhile drilling, when using the pressurized natural gas fluid as adrilling fluid, because quantities of the amount of gas liberated into awellbore while drilling is unsafe and too great of a quantity to beflared.